Shapley, H. (1972). Galaxies (3rd edition 4th printing 1977, Reprint 2014.). Harvard University Press. https://doi.org/10.4159/harvard.9780674421806
Chicago-Zitierstil (17. Ausg.)Shapley, Harlow. Galaxies. 3rd edition 4th printing 1977, Reprint 2014. Cambridge, Mass: Harvard University Press, 1972. https://doi.org/10.4159/harvard.9780674421806.
MLA-Zitierstil (9. Ausg.)Shapley, Harlow. Galaxies. 3rd edition 4th printing 1977, Reprint 2014. Harvard University Press, 1972. https://doi.org/10.4159/harvard.9780674421806.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.